Air brake compressor



M y 16, 1961 E. STUMP 2,984,405

AIR BRAKE COMPRESSOR Filed May 25. 1955 I F 7 l3 4'; r m 2 \Ill 8 ll 20 1 25 I7 fizz 22 4a 7 44 L i 8 \V/ 2/ H 1 l5 l3 /2 23 v 5 I l is E i l L av] k TOBMKE INVENTOR I F4; 3 EUGEN sTuMP v w k By Muddy.

HIIORIVEYJ.

iJnire tes 2,984,405 AIR BRAKE COMPRESSOR Filed May 23, 1955, Ser. No. 510,300 In Germany Aug. 26, 1949 Section 1, Public Law 690, Aug. 8, 1946 Patent expires Aug. 26, 1969 3 Claims. (Cl. 230-38) The present invention relates to an air compressor for supplying the compressed air for operating'theair brake of a motor vehicle, and to the driving'mechanism for operating such air compressor.

Prior to this invention, such air compressors were designed and manufactured as a unit independent of the vehicle engine and subsequently mounted thereon, and usually driven by such engine together with other accessories or by means of rubber V-belts.

It is an object of the present invention to provide an air compressor which may be made at a considerably reduced cost of manufacture and installation and is far more reliable in operation than air compressors previously used.

A further object of the present invention is to provide an air compressor which is combined with the structure of the vehicle engine so as to form anintegralunit therewith.

Another object of the invention is to provide an air compressor, the piston of which is actuated by the valve control shaft of the vehicle engine.

A feature of the invention for accomplishing. this object consists in providing a suitable cam on the valve control shaft of the engine, and a piston rod for the compressor piston which is operated by such cam, and a return spring forholding the piston rod in engagement with the cam at all times.

According to one preferred embodiment of the invention, the compressor cylinder is mounted laterally on the crankcase of the vehicle engine, and so that the longitudinal axis of the cylinder lies transverse to the longitudinal axis of the engine and within the transverse central plane of one of the cylinders of the engine, while the driving cam for operating the compressor piston is mounted between the valve control cams of such engine cylinder.

Further objects, features, and advantages of the present invention will be apparent from the following detailed description of one preferred embodiment thereof as well as from the accompanying drawings, in which Fig. 1 shows a vertical section through the compressor cylinder and the driving mechanism thereof, and taken transversely to the longitudinal axis of the driving engine of the vehicle;

Fig. 2 shows a horizontal section taken along line 2-2 of Fig. l; and

Fig. 3 is a side view of an engine illustrating a plurality of engine driven compressors interconnected in series.

Referring to the drawings, the working cylinder 3 of the air brake compressor according to the invention is preferably mounted laterally on the crankcase 4 of the internal combustion engine which supplies the driving force of the vehicle, and transverse to the longitudinal axis 46 of such engine and within the transverse central plane 4a of a cylinder 5 of the engine. The cylinder head 6 of the compressor is provided in the usual manner with self-acting air inlet and outlet valves which are not specifically shown in the drawings, as well as with Patented May '16, 1961 ice sockets 7 and 8 for connecting the air inlet and outlet lines thereto. The compressor piston 9 which is tightly slidable in the working cylinder 3 is securely connected to a hollow cylindrical piston rod 10 which, in turn, is slidably mounted in a guide casing 11, and. carries on its inner end 12 a roller 14 which is mounted on a hollow pin 13 so as to be easily rotatable thereon. This roller 14 of the plunger 10 is held constantly in intimate engagement with the drive cam 16 of shaft 17 by means of a coil spring 15. For this purpose, spring 15 acts with one end upon the bottom 18 of the hollow plunger 10 and with the other end upon a stationary pin 20 which extends transversely through the guide casing 11 of the plunger and is secured at a point 19 in the wall of the working cylinder 3. Longitudinally extending slots 21 which are provided in the wall of the hollow piston rod 10' allow the latter the necessary freedom of movement in the direction of its longitudinal axis and also prevent it from turning about such axis.

Shaft 17 constitutes the camshaft of the combustion engine. It is driven in the customary manner by the crankshaft 22 through gears or the like and carries two earns 23 for each cylinder of the engine. These cams 23 act upon the push rods or tappets 24of the inlet and outlet valves of such cylinder in such a manner that the valves will be opened at the proper times. The drive cam 16 for the compressor piston 9 lies intermediate the two valve control cams 23 and is made of a size and degree of eccentricity so as, on the one hand, to provide a sufiiciently large stroke for the compressor piston 9 and, on the other hand, to maintain the moments of force resulting from the acceleration of the piston within admissible limits, and also to permit the cam shaft 17 to be easily installed and removed through the bearing apertures 25. If for some reason a single compressor cylinder should not be sufiicient to supply the amount of compressed air required, several such cylinders may be easily provided in series one behind the other in the longitudinal direction of the driving engine as seen in Fig. 3. In such a case, each compressor cylinder insofar as its position is concerned is preferably coordinated in the manner as above-described with one cylinder of the combustion engine or the valve mechanism thereof. The side view of the engine in Fig. 3 discloses four cylinders a, b, c and d atop the engine crankcase 2. Four respective compressors f, g, h and i, projecting laterally from the respective cylinders, are each arranged with their axes located on a central plane of the cylinder transversely of the engine and indicated by the lines I, m, n and 0. The compressors of Fig. 3 are connected in series between the inlet 1' and the outlet k and are driven by the cam shaft 17 which is not shown in Fig. 3 but is located at the level of the line q behind the compressors, the cam shaft being driven by conventional means from the main crankshaft of the engine having its axis at p.

The operation of the air compressor and its driving mechanism will be clearly apparent from the above description thereof. In the course of every two revolutions of the crankshaft, the compressor piston 9 will once be moved outwardly by the cam 16 and then again back inwardly by the action of spring 15. During the inward stroke, the compressor piston 9 sucks air from the outside through the self-acting inlet valves into the chamber 26 of the compression cylinder 3 above the piston head, compresses such air in this chamber 26 during the following outward stroke, and after reaching the desired pressure conveys the air through the self-acting outlet valves of the compressor to the tank for storing the compressed air required for braking.

The application of the basic concept of the present invention is not limited to the particular embodiment described above and shown in the drawings. Thus, it is possible, for example, to provide the compressor cylinder so that its longitudinal axis extends intermediate two cylinders of the main engine of the vehicle. Also, the drive cam for the compressor piston may be provided with two raised portions so that the compressor piston will carry out two working strokes at every revolution of the valve control shaft.

Although my invention has been illustrated and described with reference to the preferred embodiments thereof I wish to have it understood that it is in no way limited to the details of such embodiments or to the specific examples described, but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. In combination with an engine of a motor vehicle, a compressor for supplying air to the air brake of the vehicle, said engine including valve control shaft means provided with actuating cam means, said compressor comprising compressor cylinder means, piston means slidably arranged therein including hollow piston rod means, said piston rod means including roller means operatively connected with said actuating cam means for moving said piston means in at least one direction of reciprocation, said roller means having a rotating axis generally parallel to said shaft means, said hollow piston rod means being provided with slots at opposite wall portions and extending in a longitudinal direction thereof, guide pin means rigidly supported in said compressor cylinder means and extending through said slots for guiding said piston rod means and preventing rotation of the latter and thereby preventing change of direction of said axis during reciprocation, spring means within said hollow rod means and acting upon said pin means and said hollow rod means for moving said piston means and piston rod means in the other direction.

2. In combination with an engine of a motor vehicle, a compressor for supplying air to the air brake of the vehicle, said engine including a crank case containing a valve control shaft means provided with actuating cam means, said compressor comprising compressor cylinder means, piston means slidably arranged therein including a compressor piston and a hollow piston rod means of smaller diameter than said piston and being operatively connected with said actuating cam means for moving said piston means in at least one direction of reciprocation, said hollow piston rod means being provided with slots at opposite wall portions and extending in a longitudinal direction thereof, pinflmeans rigidly supported in said compressor cylinder means, and extending through said slots for preventing rotation thereof during reciprocation, means for engaging and guiding said piston rod means for reciprocating movement, said guiding means including means providing for communication between said crank case and said piston means, and spring means within said hollow piston rod means and acting upon said pin means and said hollow rod means for moving said piston means and said piston rod means in the other direction.

3. A combination according to claim 2, wherein said engine includes a plurality of engine cylinder means, a plurality of compressor means including piston means, a plurality of actuating cam means provided on said valve control shaft means each operatively connected to a respective one of said piston means for reciprocation thereof, said compressor means being pneumatically connected in series with each other.

References Cited in the file of this patent UNITED STATES PATENTS 591,841 Heaven Oct. 19, 1897 1,089,419 Loomis Mar. 10, 1914 1,246,919 Herring Nov. 20, 1917 I 1,322,377 Utterbaugh Nov. 18, 1919 1,377,583 Human May 10, 1921 1,382,453 Barbetta June 21, 1921 1,385,332 Barbarou July 19, 1921 1,405,397 Camburn Feb. 7, 1922 1,843,939 Wheeler Feb. 9, 1932 1,889,396 Babitch Nov. 29, 1932 2,012,819 Hueber et al Aug. 27, 1935 2,021,857 Hueber Nov. 19, 1935 2,022,643 Hueber et al. Nov. 26, 1935 2,283,713 Wolf May 19, 1942 2,315,907 Starr Apr. 6, 1943 2,625,144 Stewart Jan. 13, 1953 FOREIGN PATENTS 599,667 France Oct. 23, 1925 

